2015 BMW M3 and M4 Prototypes

Six turbocharged cylinders, electric power steering, and a diet.

“Someone has hit a cone,” says BMW DTM driver Augusto Farfus, not to state the obvious but to make it known that he intends to be the second person to run over that same cone. Thunk. “We’ll just move it back into place.” No need to worry about damaging the car he’s thrashing around BMW’s Driving Experience Center at Maisach, Germany; this is a battle-scarred prototype, still wearing a car-camo bikini to draw out the slow striptease of the 2015 BMW M3 sedan and M4 coupe. The drip-drip-drip of information is just as painstaking, with executives and engineers playing coy in response to questions they deem too prying. Truly tortuous, though, is the fact that, although we’re among the first journalists to experience the 2015 M3 and M4, we’re merely passengers today.

Spending the better part of the day hanging around M3s and M4s was hardly a loss. What we learned is enough to stir some controversy while finally putting a few wild rumors to rest. Take the engine, for example, which is sure to raise a hullabaloo with a few M faithful. The F80 M3 sedan and the F82 M4 coupe come armed with a powertrain BMW enthusiasts know well but is a first for 3-series–based Ms: a twin-turbocharged 3.0-liter inline-six. As Farfus exits the corner and starts to pour on the power, the M4’s rear tires scrabble for traction, chattering, stuttering, and even hopping a bit as the meat attempts to cope with the twist. It’s behavior familiar to anyone who has driven the BMW 1-series M coupe. When the car fully hooks up, we rocket down the runway on a wave of torque that checks in at 369 lb-ft tall and 3200 rpm wide. Even as we lament the loss of natural aspiration, it’s hard to argue with that.

BMW Concept M4 Coupe

Despite its similarity to the 1 M’s N54 engine in concept and characteristics, this inline-six is an all-new, M-developed unit. (BMW wouldn’t divulge the M3/M4’s engine code yet.) Its turbos are smaller and can reach a higher maximum boost pressure of 18.1 psi. It is equipped with VANOS variable valve timing, Valvetronic variable lift on the intake valves, and direct injection, and it’s fortified by a forged steel crankshaft, a water-to-air intercooler, and a dry-sump oiling system. Compared with the previous M3’s naturally aspirated V-8, the inline-six offers 74 additional lb-ft of torque, as well as 16 more horsepower for a total of 430. Will it raise your blood pressure if we point out that the 1-series M made 1 more pound-foot of torque with its overboost function?

A free-revving engine is a cornerstone of what makes M cars special, so Farfus spins the engine to its 7500-rpm redline—where it’s still making maximum horsepower—before grabbing the next gear with the six-speed manual. A seven-speed dual-clutch automatic is again optional.

The M3’s exhaust note is deeper and louder than that of a 335i, but not radically different. It sounds most distinctive during gearchanges, when the engine emits a hollow burp on upshifts and staccato brap-brap-brap on downshifts. Exhaust gases always exit from all four tips, but two electronically controlled butterfly valves bypass the muffler’s restrictive routing to raise the volume under aggressive throttle. The sound isn’t all hot gas and steel pipes, though. As does the M5, the M3 complements the soundtrack by using stereo speakers to amplify the engine’s natural frequencies, but we’re too distracted by Farfus talking his way through the session to take in the acoustics from the passenger seat.

“Someone has hit several cones [here, too],” Farfus points out as we enter the slalom. Thunk. Thunk. “It was not me. I hate hitting cones.” Thunk. A solid-mounted rear subframe, tweaked suspension geometry, and wider Michelin Pilot Super Sport tires are among the chassis changes we’re experiencing. Farfus is running with the steering, powertrain, and optional Adaptive M suspension all set to their hardest-core setting, Sport Plus. As the car jockeys from left to right and back with velvety transitions, Farfus professes his love for this lighter-feeling M4.

Model Research

*AccuPayment estimates payments under various scenarios for budgeting and informational purposes only. AccuPayment does not state credit or lease terms that are available from a creditor or lessor, and AccuPayment is not an offer or promotion of a credit or lease transaction.